Question #1424
A solutions architect is designing a web application hosted on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer. The application experiences high traffic during business hours (Monday-Friday) and does not need to run on weekends. Which combination of actions should the architect take to ensure scalability and cost efficiency? (Choose two.)
Use AWS Auto Scaling to adjust the ALB's capacity based on incoming connections.
Use AWS Auto Scaling to scale the NAT gateway's capacity dynamically.
Deploy EC2 instances across multiple Availability Zones to enhance availability.
Apply a target tracking scaling policy based on network inbound metrics.
Configure scheduled scaling to set the Auto Scaling group's capacity to zero during weekends, resuming normal limits on Mondays.
Explanation
The correct answers are D and E. Here's why:
- D (Target Tracking Scaling Policy): This allows the Auto Scaling group to dynamically adjust the number of EC2 instances based on metrics like network inbound traffic, ensuring scalability during high-traffic business hours.
- E (Scheduled Scaling): Configuring the Auto Scaling group to scale to zero on weekends stops all instances, reducing costs when the application is unused.
Why Others Are Incorrect:
- A: ALBs scale automatically; manual adjustment isn't needed.
- B: NAT gateway capacity is fixed and managed by AWS.
- C: While deploying across AZs improves availability, it doesn't directly address scalability or weekend cost savings.
Key Points: Use scheduled scaling for predictable downtime and target tracking for dynamic traffic. ALB/NAT scaling isn't user-managed.
Answer
The correct answer is: DE